PAL runs at 25 frames per second (FPS) and was adopted in mainly the Western European area. It was made when NTSC showed several weaknesses in being unable to keep consistent tone colour under poor transmission. The first broadcast to the United Kingdom and West Germany in 1967 which was used initially by BBC 1 and 2.
SECAM runs at the same FPS as PAL and first began as SECAM 1 in 1961. It adopted in mainly communist Eastern European as well as France. However since PAL was created most Eastern European countries and African countries which used to use SECAM changed to using PAL. France is the only country that didn't change and continued to use SECAM. SECAM however has different colour outputs meaning the same program may be running on different channels with slightly different colour tones.
NTSC named after the National Television System Committee was used mainly in most of America, South Korea, Japan and some Pacific Islands etc. In 1953 the second NTSC was adopted, which allowed colour television which was compatible with the existing black and white receivers. It was the main television standard until the 21st century when it was replaced by ATSC.
Broadcasting systems are made up of radio stations, one of the first kind was terrestrial television which uses radio signals to transmit to antennas. The BBC began broadcasting using this method in 1929, there was practically no other way to broadcast tv until the 1950s which sparked the beginning of cable television. During the 1970s and 80s cable tv took over as the most common way to receive tv and terrestrial declined, however it picked up a little during 2010 with the introduction of digital tv.
Cable television is a system of distributing television to paying customers through subscriptions. The tv is delivered through radio frequency signals transmitted through cables or light pulses through fibre optic cables. This is almost the direct opposition to tv delivered through terrestrial's method of radio signals to antennas. A large advantage that this method has over terrestrial is that the same cables can be used to provide high speed internet, telephone services and some non-television services. This is why companies that use cable sell multiple deals and bundles so that the different services can be provided in the best combination that is appropriate for the customer. For example Virgin Media offers the cheapest bundle at £26.50 a month for those who only want fibre optic broadband with unlimited downloads and it's most expensive bundle that includes broadband, tv, phone and SIM from up to £50 a month.
Satellite television as it's name suggests involves sending television through a communications satellite which is received through an antenna. This used to be done through analog signal but now is generally replaced by digital since digital offers a much better quality picture. Companies like sky use this in a similar way to cable using subscriptions and bundles but with more focus on a wider range of television programs rather than internet. For example Sky will sell The Family bundle for £32 a month that includes over 80 channels, 240 free to air channels, Sky+, Catch up TV, On Demand and over 50 HD channels.
TV stations like satellite (Sky), cable (Virgin/Broadband) and the internet (BBC I player) are part of digital TV which instead of broadcast through satellite like analog TV they broad cast through the internet. Systems such as Freeview is free for everyone as long as they have a TV licence however the quality is usually standard while other systems such as Virgin or Sky while they can be expensive offer much more variety and choice and at a higher quality.
PAL has a resolution of 720 X 576 which is the same as SECAM but NTSC has a resolution by 720 X 480 this means that NTSC has a higher resolution meaning there are more pixels to create a smoother picture.
The difference is that an analogs TV signal is transmitted through radio transmissions and electromagnetic signals meaning that only bits of the signal is received, this can result in a static picture. While digital TV is broadcast as compressed signals of binary codes meaning more of the signal is received and in more detail of what should appear on screen, resulting in a better picture. However this can be a disadvantage since streaming videos from the internet relies on the provider which can sometimes become slow leading to buffering videos and slow signal. However another advantage of digital is that internet users do not need a TV licence to watch TV on I Player or 4OD etc as long as the shows they watch are not live.
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